I have a pc with two hard drives, one runs Ubuntu 10.10 and the other has NTFS with a broken XP. The XP failed after I upgrade Ubuntu to 10.10. I installed virtualbox in Ubuntu so for a while I was happy with the setting.
Recently I needed to revive the XP to a dual boot since I need to test a piece of hardware that cannot be done in a virtual machine setting. So I inserted the XP install CD and rebooted the machine. When I hit the return to install XP, I noticed that the XP install CD did not recognise hard drives correctly: reporting the linux hard drives in a much smaller sizes and as C drive of unknown type. For the second drive, it reports a few unpartitioned space and an NTFS partition. I tried to see if I can install XP in the unpartitioned space but failed. For fearing erase my linux hard drive, I decided to abandon the effort. However the damage is already there: Ubuntu 10.10 is gone.
I booted the machine with a Ubuntu 10.10 live CD, it could not recognise the linux hard drive any more. Testdisk told me that the linux hard drive is now in a FAT file system. I tried a few testdisk commands in vain to restore any linux partition and then I realised I had better stop messing with it further.
In this case, what is the best way, if any, to recover the partition and data in the linux hard drive?